Width maintainer



Dec. 17, 1929. E. T FERNGREN 1,739,

WIDTH MAINTAINER Filed Dec. 1, 1924 2 Sheets-Sheet 1 INVE N T UH- Enoch TF/"ngren,

AT T D'RNEY,

Dec. 17, 1929. E. T. FERNGREN Q 1,739,959

WILDTH MAINTAINER Filed De0.-1, 1924 2 Sheets-Sheet 2 INVE N T [J R- 0004) 'ZZ'Erngnen.

ATTORNEY.

Patented Dec. 17, 1929 Um 'irso "era res PATENT OFFICE ,ENOCH T. I

wmrn: mamramnn.

mom; or 'roLEno, 01:10, ns'srenor. r 'rnsm-ownns' GLASS comrm, or ronnno,;onro, A conromnon or onto Application med December 1, 1924. Serial No. 753,108. 4

The present invention is an improvement in the art ofdrawing sheet glass, and relates more particularly to ainethod and apparatus for maintaining the width of the sheet, and to means for making it possible to produce a wider sheet.

' mechanism and into a leer. .As is well-known l sheet is left.

- 29 in the art, some means must be provided to maintain the width of the sheet drawn, other-' wise it will gradually narrow away until no The prior art structures make use of so-called knurled rollers which are usually positioned in the meniscus at its opposite ends by which the sheet isprevented from narrowing accordingto itsnormal tendency. These knurled rollers have however made it necessarv to cut of? n substantial 'width of sheet section-from the finished sheet due to the fact that the combined action of I moved as abovepointed out.

the rollers and the supplemental air cooling normally employed causes a thickened portion to extend inward on the sheet a substantial distance from the edge so that it is necessary to remove this thickened portion before obtaining thickness of sheet. i

' An important object of the invention is to provide animproved type of roller for use in connection with sheet glass drawing apparatus which is adapted to maintain the. widthof the sheet'desired while at the same time it will cut down to a considerable extent the amount of glass that heretofore has been re- A further object of the invention is to provide rolls for use in sheet glass apparatus which have a diameter of suflicient size to 'rolls to engage the sheet supplying source subfore it merges into the sheet thickness.

net width of the desired.

'prpduce an outer surface of substantially the g same curvature as the normal curvature of the sheet source. I I

A still further object of the invention is to provide a roll of this-nature which has a diameter sufliciently large enough to permit the stantially up to such a point in the time of draw thereofwhere the said sheet suppyling source has an approximate linear advance be- A still further object of the invention is to provide width maint-aining means for use in sheet glass apparatus' wlierebythe edge portions of the sheetbeinfg-jprmed are built up' in a manner to hold the shetto' width" by'passin 3 or moving the border lass forwardbetween rolls Which have a peripheral speedisubstantially the same as the speed of the adjacent glass which is being moved inthe line of draw.

Still another "object of. the invention is to 7 provide rolls for use as width maintainers in sheet glass apparatus having a cupped end suitable for entrapping heat currents present around the surface of the glass from which the sheet is being drawn to prevent the cooling action of the rolls extending throughout the entire length thereof, thus making it possible to accurately control the width of the thickened portion formed on the sheet to hold the same to width.

Other objects and advantages of. the invention will become apparent during the course of the following description.

In the drawings wherein like'num'erals are employed to designate like parts throughout the same: fi Fig. 1 is a fragmentary sectional view of one type of sheet drawing apparatus illustrating the invention in use.

Fig. 2 is a top planview of the width maintaining means in one form of mounting therefor. f x

Fig. 3 is a fragmentary transverse section Fig. 4 is a sectional detail of the drive used.

(Fig. 5 is another sectional detail thereof.

Fig. 6 is an end-view of the knurls illu's-j trating their position when in use.

Fig. 7 is atop planyiew of the rolls, one

of which is section for the purposes of illustration.

Fig. 8 is a View similar to Fig. 6, showing I the rolls pointed in opposite directions.

I the bottom to keep the glass in condition for drawing purposes, but this construction is not illustrated. The sheet 17 is drawn from the molten mass 16, and is run a short way in avertical plane, and as is shown is then bent over a bending roll 18 and is passed through suitable drawing mechanism and an annealing leer.

In the prior art to prevent the sheet 17 from becoming narrower and narrower until finally no sheet is left, cylindrical so-called knurled rollers are employed and are positioned at the ends of the meniscus 19 to mechanically retard and build up a thickened edge portion 20 to hold the sheet to the desired width. The prior .art knurled rollers will function'as width maintainers, but they have several objectionable features in that, due to their action uponthe glass, they create a thickened sheet body section next to and inside of the regular edge portion 20 which does not end abruptlybut which. tapersout for a considerable distance toward the inner sections of the sheet, thus making it necessary to remove a considerable width of glass from both sides of the'sheet when cutting to get a sheet of thedesired thickness. Also the uniform cylindrical shape given to most types of prior art edge formin dies or rollers makes for a substantially like peripheral speed and pressure against the edge forming glass at the point of its advancement or. release by or from said rollers. This causes the formation of a knurled edge border which is relatively thin as compared to the thickened sections before mentioned, which difierence makes for much irregular contraction and expansion during the cooling period of the sheet, and causes considerable loss on the slightest provocation through the warping and breaking of the sheet while in transit through the leer.

The low point of operation which is necessary for a prior art roller, if it is to function in a useful manner, also is a disadvantage resulting in contraction in width of sheet and a wave condition across: its forming zone proper, due to that at the point at which it is made the edge of sheet must necessarily be driven forth by the rollers at a speedier ratio than the glass formin the adjacent drawn portion 0 the base 0 the sheet where the relative speed progression of the glass in the direction of draw is very slow, which relationships cause the partly chilled knurled edge as it comes into being and is driven forth fromthe gripping point of the rollers to angle or 'curve over toward the most adjacent sheet section in the making below the sheetarea proper and'above the base of the. sheet,

which means a loss in sheet width at each edge of the sheet and a loss of tension both lengthwise and crosswise of the sheet area.

The reason why the rollers of the prior art cannot be driven at a slower peripheral speed at the point at which they are operated to produce a condition where the knurled edge, instead of being driven forth, would be pulled out by the drawing force from between the gripping point of the rollers, resides in that the edges of sheet would stretch entirely too thin and vwould thus cause breakage of sheet, and that the eneral retardment of the glass advancesupp ying the line of draw adjacent the edges of the sheet attracts the glass from the center of the sheet towards its edge por= tion and causes the sheet to draw thin centrally, and that when the glass movement is thus restricted at the edges by slow moving rollers and not along the base of the sheet area, the glass finally pulls out of the grip of the knurled rollers being supplied to the edge portions of the sheet from adjacent points where the resistance to the glass movement is less.

On the other hand if the rolling dies of the prior art are operated at the edges ofthe drawn glass formation where the drawn .speed of the glass at the point of grip of the rollers would be about the same as the peripheral speed of the rollers, which asnow An important object of this invention is to cut down to a considerable extent the amount of glass which has heretofore been wasted when forming the border portions 20, but at the same time it is also an object to build a I thicker edge on the sheet,-and one in which its thicker and thinner portions are so related to each other and to the glass sheet body as to carry forward sufiicient heat to prevent breakage in the leer, while at the same time being strong and stifi enough to hold-the stressing glass to full width at the points of- 1' its tapering progression toward fixed'thickness of sheet formation.

As is shown clearly in Figs. 6 and 7, rolls 21 are employed for the purposes ofb'uilding up the border portion 20 on the sheet 17. have designed the rolls 21 in a'manner that area-etc adjacent glass.

roduce'an outer curvature 22 as'shown in ig. 6 which is substantially the same-curvature as the normal curvature'of the meniscus. or sheet-supplying source 19.. As is shown,

the rolls 21 bite into the hiss 'a'slight bit, but are not submerged to t e extent that the present type of knurls are. By increasing the diameter of the knurled rollers it is possible to grip or remain in 'contact with the glass a greater length of time with the sheetsupplymg meniscus 19 than has heretofore been possible. It is necessary tov keep the knurled rollers down at the base of the meniscus as shown in Fig. 6, and it is ossible to do this with the rolls as shown whi e at the same time it .is also possible to keep the knurled rolls in contact with the glass to a point where the sheet-supplying meniscus is substantially merged into the sheet thickness.'-"

The glass near'the top of the meniscus is moved more rapidly than the glass lower down nearer the base due to the difference in. quantity present. With the present form'of rolls it is possible to get a peripheral speed which is substantially the'same speed as the In other words, the glass leaving the knurled rolls is moving at substantially the same speed as the speed ofthe draw of the sheet. This is a-decided advan-I tage over the prior art structures in that. no strains or over-supply of lass is introduced into the sheet being forme The rolls 21 are preferably. provided with an outer slightly tapered knurled ortio'n 23 and an inner curved reduced end 24. The reduced end is cupped out or recessed'as at 25. As i shown in Fig. .7, the rolls. 21 are internally cooled by a cooling medium- 26 introduced through the pipe 27 and carried ofiby the pipe 28 housing the pipe 27. A

. quantity of the cooling mediiunis at all times within the knurled-roll 21, in the chamber29. The cooling medium is used to prevent overheating of the knurled rolls and also w toabsorb heat from'the border. portions of I the sheet so that the said border pprtions will be sufliciently viscousto maintain andhold the sheet to width. However withithe use of the knurled rolls here described,- it is os- Y sible to build up a good heavy uniform or I sheet for use. To restrict the cooling action der portion which does not necessarily have to be wide. In fact, it is one of the important objects of this invention to keep the border portion relativel narrowso that but a relatively narrow e ge strip of the drawn glass. will have to be removed .when' cutting up the to the extreme border sections of the sheet 17, the cupped ends'25 are provided. These cupped ends or recessed ends form a pocket-.'

for the reception-oi heat currents which are present around the surface of the glass from which the. sheetis being drawn. The heat currents will have a tendency to counteract tralize, the col -to. a great extent or tubes 28 extend a substantial distance from the ic'ooling action of the cooling medium inthe entire. roll. The. progressively reduced area of actual contact WhlCh is had with the glass toward the most .forward' impression point of the cupped or open walled section of thechamber 29, andwill prevent cooling of l the knurls or rollers will correspondinglyre- -"sorhing and conducting capacity of each roller-is at its minimum, resulting in that the glass which is subject to the rolling touch-of the cupped ends of knurls will build up a sli ht beaded or thickened portion which wi run along the inner side of the knurled sectionadjacent to the" thinner ,portion of the ed e which is formed where the rollers exert't eirgreatestpressure against the glass. Of course this heating action at the end will not materially interfere withthecooling action of-the extreme border section' 'of the sheet, .butwill prevent the coolin action from spreadingout over a considerable'distance.' 'Even though the glass going into the sheet should come in contact with the end 24 of the roll, itv would not cool the glass sufiiciently to cause it to build up: a heavy edge, and for this reason the heavy edge 20 formed on the sheet will be restricted to substantially that portion of the sheetwhich comes in con tact with the cool area of the roll 21. The .shape of edge which will be formed by this 31 due to their di erence in size. The heat I zones'orthickdportions 30 will tend'to. neuportion 31-, thus preventing reakage of the sheet during the-rest'of its treatment. The outer thick port-ion 30 is formed between the-knurled sections on the ,rolls, while-the smaller inner enlarged section is formed by the reduced end 24 of the rolls as is clearly shownin Fig. 7. It will-be seen that the knurled roll 21 will have its. greatest peripheral speed at the joinder. of the knurled surface and the Y smoothed surface, while at the same time less glass will be fed u through these-points.

The rolls 21 may e'mounted in any desired-- manner so that the can be toed in as in Fig.

9, or toed out as in ig. 10. The t pe of edge and size of edge can be controlled y the rela- '12o tivepositions of the rollsas well as b the speed-at which they. aredriven'. 'In F1gs. 2 mes 'is'shown one embodiment of mounting which may be used. In this form the pipes the drawpot 1.5,and have carried thereon gear wheelsz32 and.33." The gear wheel 32 iscarried by a universal connection 34 so that the tube 28 can be moved relatively to the same. The

gear wheels 32 are adapted to mesh. with the 1 the gear 32 is relatively longer than the other a sothat the tubes 28 can be moved to and from each other without interfering with thedri'v- Worms35 carried on a transverse power shaft 36. As is shown the worm 35 meshing with ing thereof. In this .embodiment the tube carrying the gear 32 is mounted on a post 37 rotatable in a sleeve 38 which is carried on a slide 39. By manipulating the shaft 40 the sleeve and shaft 37 and 38 respectively can be moved to separateor bring closer the tubes 28, thus regulating the relative positions andangles of the two knurled rollers 21.

In operation, it is desirable that the diamstar of the knurled rollers 21 be of such a size that the outer surface will have a curvature substantially the same as the natural curvature of the sheet supplying meniscus so that the said roll will be in contact with the meniscus to a point substantially where it merges into sheet thickness. The rolls are also driven at a speed, and due to their size wherein the peripheral speed will permit the glass to leave the rolls at a speed that is substantially the same as the speed of draw of the sheet. Due

to the speed of the rolls and the temperature controlling action of the cupped end 25, it is possible to maintain the sheet to width without making it necessary to cut off a considerable width of the sheet. By using the cupped knurled rolls as described, the edge which is formed on the sheet, will be relatively thick, heavy and narrow. The cupped end can be made in any design or can be modified to give the best results, but it is to be understood that the utilization of the heatcurrents from neanthe surface of the sheet glass in the drawpot 'will'considerably aid in preventing the thickenededge 20 from spreading out toward the'center of thesheet. v

' It is to be understood that the 'form of the invention herewith shown and described is to be'taken as the preferred embodiment of the same, and that various changes in the shape,

size and arrangement of parts may be resorted 2. In a sheet glass drawing apparatus, 7 means for drawing a flat sheet of glass from a mass of molten glass, and rotatable rolls engaging the edges of the sheet at its source,

each of said rolls having a recess in one end means'to restrict t rolls upon the sheet to produce a relatively of the subjoiried claims.

given off from the molten glass from which the sheet is drawn.

- 3. In a sheet glass drawing apparatus,-

means for drawing a flat sheetof glass from a mass of molten glass, and means for holding the sheet to width," comprising rotatable rolls engaging the-edges of the sheet near its source, each of said rolls having a cupped 4. In a sheetglass drawing apparatus, means for drawing a fiat-sheet of glass from a mass of molten glass, and means for holding thesheet to width, comprisingrotatable rolls engaging the ed esof the sheet near its source, a portion of said rolls having a knurled surface, one end ofsaid rolls being reduced 'in diameter. and having a recess formed therein.

5. In a sheet glass drawing apparatus,

means for drawing a flat sheet of glass from a mass of molten glass, and means for holding the sheet to width, comprising rotatable rolls, the peripheral speed being such thatthe glass leaving the rolls will have substantially the same speed at which the adjacent glass is drawn, means to cool the rolls, and means to restrict the cooling to the outer portions thereof.

6. In a sheet glass drawing a paratus,

means for drawing a flat sheet of g ass from a mass of molten glass, and rolls engaging the edges of the sheet near its source for building up a relatively heavy ed e portion to hold the sheet to width, the perip eral speed there of being such that the glass at the point where it leaves the rolls will have substantially the same speed as the s eed of draw of the sheet, means to adjusta 1 rolls for rotation, means to chi the rolls to assist in building 111pl e cooling actionof the said edge portion, and

mount the I narrow thickened edge portion onsaid sheet.

7 A roll for use in sheet glass apparatus having a recess therein in the end-opposite to the end by which said roll is supported.

8. A roll for usein sheet glass apparatus having a relatively large diameter, and having a recess therein in the end opposite to the end by whichsaid roll'is supported.

9.'A roll for use in sheet glass apparatus having 'a' slightly tapered knurled portion, and having a recessed end at the opposite end to which the roll is supported. f:

10. A roll for use'i'n sheet glass apparatus having a slightly tapered knurled portion,

"and having a. curved reduced and o posite,

thereto, said end having a recess ormed therein.

Signed at Toledo, in the county of Lucas,

and State of Ohio,this 29th dayof Nov.,

ENOCH T. FERNGREN.

for receiving aportion of the heatcurrents 

